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CHD Genetics Part II
Published in Mark C Houston, The Truth About Heart Disease, 2023
There are several issues we want to define in patients. One is their genetic profile, the genes they were dealt. There are also epigenetic influences that are not genetic that alter the function of deoxyribonucleic acid (DNA) in many different ways that can affect future generations. These are called methylation, histone modifications, and noncoding messenger ribonucleic acids (RNA). These influences are not in the genetic code but can be passed on from mother to fetus and from generation to generation. For example, a mother that is malnourished during pregnancy is more likely to have a child that develops hypertension, diabetes mellitus, or obesity later in life. The risk for these diseases can then be passed on “epigenetically” to future generations. The final aspect is gene expression, as genes express themselves in response to nourishment or insults from different types of information coming in from the environment. Genetics has become important in determining not only the best nutritional program but also medication use in many patients, based on their genetic profiles.
Cancer Biology and Genetics for Non-Biologists
Published in Trevor F. Cox, Medical Statistics for Cancer Studies, 2022
Cancer is not one disease but a collection of diseases. It occurs when the DNA of a cell is damaged, and as there are about 200 different types of cells in the body, there can be 200 types of cancer. DNA damage is caused by mutations (changes) of the genetic code. The mutation can affect a single gene or, more widely, a chromosome.
Food Interactions, Sirtuins, Genes, Homeostasis, and General Discussion
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
The key difference between RNA and DNA structures is that the ribose sugar in RNA has a hydroxyl (-OH) group which is absent in DNA, and the thymine base of DNA is replaced by the uracil base in RNA (107, 111–113). The nucleotides that comprise DNA include adenine (A), guanine (G), cytosine (C), and thymine (T); whereas RNA nucleotides include A, G, C, and uracil (U). Moreover, RNA has only one long strand or chain in almost species, except in some viruses, while DNA has a double strand and looks like a twisted ladder in all species from bacteria and plants to invertebrates and humans (107, 111–113). DNA is defined as a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms. The main role of RNA is to transfer the genetic code needed for the creation of proteins from the nucleus to the ribosome (111). This process prevents the DNA from having to leave the nucleus. This keeps the DNA and genetic code protected from damage. Without RNA, proteins could never be made. RNA molecules are not only involved in protein synthesis, but also sometimes in the transmission of genetic information (111).
Genetic syndromes and autoimmunity: what do we know? Focus on Down and Turner syndrome
Published in Expert Review of Clinical Immunology, 2023
Alessandra Li Pomi, Malgorzata Wasniewska
Patients affected by genetic diseases, such as Turner syndrome (TS), Trisomy 21 or Down syndrome (DS) and 22q11.2 deletion syndrome (22q11.2DS), often present autoimmune disorders, from the most common thyroid disorders to celiac disease (CD), but also type 1 diabetes (T1D), rheumatological disorders such as juvenile idiopathic arthritis and systemic lupus erythematosus (SLE) and cutaneous disorders such as vitiligo and alopecia [1]. In these syndromes, alterations in various genes are probably responsible for the increased prevalence, the earlier onset and the atypical evolution of ADs. Nevertheless, the underlying pathophysiological mechanism has not been completely explained. New insight into identification of causative variants of autoimmune diseases and their association with genetic syndromes is represented by new technological developments, such as next-generation sequencing technologies. Specifically, genome-wide association studies (GWAS) can provide an unbiased view of the biological pathways that drive human autoimmune diseases [3]. The technique uses the knowledge of single nucleotide polymorphisms (SNPs), which are common single-letter changes in the genetic code, comparing the frequency with which they occur in people with the disease and with people without the disease. An intensive study of the genetics underlying autoimmune diseases could offer also new therapeutic targets [3].
The human antibody sequence space and structural design of the V, J regions, and CDRH3 with Rosetta
Published in mAbs, 2022
Samuel Schmitz, Emily A. Schmitz, James E. Crowe, Jens Meiler
The genetic code is degenerate, such that 64 unique nucleotide triplets in the standard translation table encode the 20 canonical amino acids. Thus, some amino acids are encoded by multiple nucleotide triplets and different amino acids share the same nucleotide in 1 or 2 positions of the nucleotide triplet. HL was previously described as independent single nucleotide observations,12 suggesting that the antibody maturation process is a stochastic process that mutates single nucleotides independently. We therefore postulate that all single nucleotide frequencies not only inform about the frequency of their encoding amino acid, but also inform the likelihood of observing another amino acid at that position, which is partially encoded by the same nucleotides of a different codon. In this study, we employ Bayesian statistics to model the probability of observing amino acids in human antibodies and postulate that the resulting amino acid frequencies model a larger human sequence space than has been observed, with the potential to suggest probabilities for amino acids that have not directly been observed at certain positions. We demonstrate that amino acid frequencies can then be used to inform computational structural protein design with Rosetta25 to generate antibodies that are antigen-specific and thermodynamically stable, while still maintaining HL.
Gaining an understanding of behavioral genetics through studies of foraging in Drosophila and learning in C. elegans
Published in Journal of Neurogenetics, 2021
Aaron P. Reiss, Catharine H. Rankin
Historically, in the study of behavior, there has been a long-standing debate of nature versus nurture, arguing whether behavior is determined by an organism’s environment and experiences or pre-determined before exposure to any external stimulus by its genes. These seemingly opposing viewpoints framed the scope of most behavioral research throughout much of the 1900s. However, due to advances in our understanding of genetics, molecular and cellular biology, and neurobiology, these differing viewpoints have been found to be intertwined; both are integral in the formation of behavior. An organism’s genetic code serves as the foundation that determines how that organism develops and functions. During development, networks of genes encode the growth and differentiation of the nervous system, the most important system in producing behavior (Sokolowski, 2001). Throughout an organism’s lifespan genes continue to produce the molecular machinery that maintain and modulate the functioning of the nervous system. Thus, an organism’s genes influence behavior significantly due to their integral role in the nervous system and throughout the rest of an organism’s body.